Placental pathology casebook. Serpentine aneurysms of the placenta with fetal consequences.

Two cases of placental surface vessel aneurysms are presented. One case was associated with severe fetal intrauterine growth restriction and fetal thrombocytopenia. The other case was associated with "molar transformation" of placental villous tissue.

Intrauterine death of a twin: mechanisms, implications for surviving twin, and placental pathology.

In multiple gestations, intrauterine death of one fetus occurs frequently. Sonographic studies indicate that many twin pregnancies are converted in early pregnancy to singletons. The "vanished" twin is sometimes recognized as a fetus papyraceous (compressus) incorporated into the placenta of the survivor.